DNA microarray for genotyping antibiotic resistance determinants in Acinetobacter baumannii clinical isolates

Area of Science:

• Microbiology
• Molecular Diagnostics
• Infectious Diseases

Background:

• Acinetobacter baumannii is a significant global health concern due to its increasing antibiotic resistance.
• Accurate and rapid detection of resistance mechanisms is crucial for effective patient management and infection control.

Purpose of the Study:

• To develop and validate a microarray for the rapid and accurate detection of antibiotic resistance determinants in Acinetobacter baumannii.
• To reduce the diagnostic lead time for antibiotic resistance in A. baumannii.

Main Methods:

• Development of a microarray targeting 91 specific DNA sequences associated with antibiotic resistance.
• Validation of the microarray using 60 multidrug-resistant A. baumannii strains in a blinded, prospective study.
• Comparison of microarray results with phenotypic susceptibility testing (VITEK2) and PCR for carbapenemase genes.

Main Results:

• The microarray achieved high accuracy, with average positive predictive value of 98%, negative predictive value of 98%, sensitivity of 99%, and specificity of 94%.
• Complete concordance was observed when comparing microarray results for carbapenemase genes with singleplex PCR.
• The assay provides results within 4 hours from bacterial culture.

Conclusions:

• The developed microarray is a reliable tool for parallel detection of multiple antibiotic resistance determinants in A. baumannii.
• The rapid 4-hour turnaround time facilitates prompt initiation of appropriate anti-infective therapy for critically ill patients.
• The microarray has potential applications in clinical diagnostics and epidemiological surveillance of A. baumannii.